Preventive and therapeutic vascular photobiomodulation decreases the inflammatory markers and enhances the muscle repair process in an animal model

• Published in: Journal of photochemistry and photobiology. B, Biology Vol. 256; p. 112921
• Main Authors: Malavazzi, Tainá Caroline dos Santos, Andreo, Lucas, Martinelli, Andreia, Rodrigues, Maria Fernanda Setúbal Destro, Horliana, Anna Carolina Ratto Tempestini, Bussadori, Sandra Kalil, Fernandes, Kristianne Porta Santos, Nunes, Fabio Daumas, Mesquita-Ferrari, Raquel Agnelli
• Format: Journal Article
• Language: English
• Published: Switzerland Elsevier B.V 01.07.2024
• Subjects: Animals; Biomarkers - metabolism; Chemokine CCL2 - metabolism; Cryoinjury; Disease Models, Animal; Inflammation - metabolism; Inflammation - pathology; Interleukin-1beta - blood; Interleukin-1beta - metabolism; Interleukin-6 - blood; Interleukin-6 - metabolism; Low-level laser; Low-Level Light Therapy; Male; Modified ILIB; Muscle repair; Muscle, Skeletal - metabolism; Muscle, Skeletal - radiation effects; Rats; Rats, Wistar; Systemic vascular photobiomodulation; Tumor Necrosis Factor-alpha - blood; Tumor Necrosis Factor-alpha - metabolism; Wound Healing - radiation effects; Modified ILIB; Muscle repair; Low-level laser; Cryoinjury; Systemic vascular photobiomodulation
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2024.112921

Photobiomodulation therapy (PBM) has shown positive effects when applied locally to modulate the inflammatory process and facilitate muscle repair. However, the available literature on the mechanisms of action of vascular photobiomodulation (VPBM), a non-invasive method of vascular irradiation, specifically in the context of local muscle repair, is limited. Thus, this study aimed to assess the impact of vascular photobiomodulation (VPBM) using a low-level laser (LLL) on the inflammatory response and the process of skeletal muscle repair whether administered prior to or following cryoinjury-induced acute muscle damage in the tibialis anterior (TA) muscles. Wistar rats (n = 85) were organized into the following experimental groups: (1) Control (n = 5); (2) Non-Injury + VPBM (n = 20); (3) Injured (n = 20); (4) Pre-VPBM + Injury (n = 20); (5) Injury + Post-VPBM (n = 20). VPBM was administered over the vein/artery at the base of the animals' tails (wavelength: 780 nm; power: 40 mW; application area: 0.04 cm2; energy density: 80 J/cm2). Euthanasia of the animals was carried out at 1, 2, 5, and 7 days after inducing the injuries. Tibialis anterior (TA) muscles were collected for both qualitative and quantitative histological analysis using H&E staining and for assessing protein expression of TNF-α, MCP-1, IL-1β, and IL-6 via ELISA. Blood samples were collected and analyzed using an automatic hematological analyzer and a leukocyte differential counter. Data were subjected to statistical analysis (ANOVA/Tukey). The results revealed that applying VPBM prior to injury led to an increase in circulating neutrophils (granulocytes) after 1 day and a subsequent increase in monocytes after 2 and 5 days, compared to the Non-Injury + VPBM and Injured groups. Notably, an increase in erythrocytes and hemoglobin concentration was observed in the Non-Injury + VPBM group on days 1 and 2 in comparison to the Injured group. In terms of histological aspects, only the Prior VPBM + Injured group exhibited a reduction in the number of inflammatory cells after 1, 5, and 7 days, along with an increase in blood vessels at 5 days. Both the Prior VPBM + Injured and Injured + VPBM after groups displayed a decrease in myonecrosis at 1, 2, and 7 days, an increase in newly-formed and immature fibers after 5 and 7 days, and neovascularization after 1, 2, and 7 days. Regarding protein expression, there was an increase in MCP-1 after 1 and 5 days, TNF-α, IL-6, and IL-1β after 1, 2, and 5 days in the Injured + VPBM after group when compared to the other experimental groups. The Prior VPBM + Injured group exhibited increased MCP-1 production after 2 days, in comparison to the Non-Injury + VPBM and Control groups. Notably, on day 7, the Injured group continued to show elevated MCP-1 protein expression when compared to the VPBM groups. In conclusion, VPBM effectively modulated hematological parameters, circulating leukocytes, the protein expression of the chemokine MCP-1, and the proinflammatory cytokines TNF-α and IL-1β, ultimately influencing the inflammatory process. This modulation resulted in a reduction of myonecrosis, restoration of tissue architecture, increased formation of newly and immature muscle fibers, and enhanced neovascularization, with more pronounced effects when VPBM was applied prior to the muscle injury. •Skeletal muscle is one of the most abundant tissues that is often susceptible to injury.•The non-invasive vascular photobiomodulation (VPBM) acting with a systemic approach.•This systemic approach eliminates the need to select or determine the treatment area.•VPBM modulated hematological parameters, leukocytes, and proinflammatory cytokines.•Preventive VPBM pronounced modulated histological aspects, enhancing tissue remodeling.